The reason Congress only slapped the ATF’s hand then instead of abolishing it and rolling its function over into the FBI was simple. The ATF employees were so marginal in performance that NONE of federal law enforcement wanted anything to do with them. ATF was considered the very bottom of the food chain and weren't readily employable by other agencies.
I suspect the same thing will happen again because the ATF has continued to spiral down since the 1970’s and its antics have gotten worse and deadlier.
Mall cop rejects.